• Linus Torvalds's avatar
    Revert "mm: page cache: store only head pages in i_pages" · 69bf4b6b
    Linus Torvalds authored
    This reverts commit 5fd4ca2d.
    
    Mikhail Gavrilov reports that it causes the VM_BUG_ON_PAGE() in
    __delete_from_swap_cache() to trigger:
    
       page:ffffd6d34dff0000 refcount:1 mapcount:1 mapping:ffff97812323a689 index:0xfecec363
       anon
       flags: 0x17fffe00080034(uptodate|lru|active|swapbacked)
       raw: 0017fffe00080034 ffffd6d34c67c508 ffffd6d3504b8d48 ffff97812323a689
       raw: 00000000fecec363 0000000000000000 0000000100000000 ffff978433ace000
       page dumped because: VM_BUG_ON_PAGE(entry != page)
       page->mem_cgroup:ffff978433ace000
       ------------[ cut here ]------------
       kernel BUG at mm/swap_state.c:170!
       invalid opcode: 0000 [#1] SMP NOPTI
       CPU: 1 PID: 221 Comm: kswapd0 Not tainted 5.2.0-0.rc2.git0.1.fc31.x86_64 #1
       Hardware name: System manufacturer System Product Name/ROG STRIX X470-I GAMING, BIOS 2202 04/11/2019
       RIP: 0010:__delete_from_swap_cache+0x20d/0x240
       Code: 30 65 48 33 04 25 28 00 00 00 75 4a 48 83 c4 38 5b 5d 41 5c 41 5d 41 5e 41 5f c3 48 c7 c6 2f dc 0f 8a 48 89 c7 e8 93 1b fd ff <0f> 0b 48 c7 c6 a8 74 0f 8a e8 85 1b fd ff 0f 0b 48 c7 c6 a8 7d 0f
       RSP: 0018:ffffa982036e7980 EFLAGS: 00010046
       RAX: 0000000000000021 RBX: 0000000000000040 RCX: 0000000000000006
       RDX: 0000000000000000 RSI: 0000000000000086 RDI: ffff97843d657900
       RBP: 0000000000000001 R08: ffffa982036e7835 R09: 0000000000000535
       R10: ffff97845e21a46c R11: ffffa982036e7835 R12: ffff978426387120
       R13: 0000000000000000 R14: ffffd6d34dff0040 R15: ffffd6d34dff0000
       FS:  0000000000000000(0000) GS:ffff97843d640000(0000) knlGS:0000000000000000
       CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
       CR2: 00002cba88ef5000 CR3: 000000078a97c000 CR4: 00000000003406e0
       Call Trace:
        delete_from_swap_cache+0x46/0xa0
        try_to_free_swap+0xbc/0x110
        swap_writepage+0x13/0x70
        pageout.isra.0+0x13c/0x350
        shrink_page_list+0xc14/0xdf0
        shrink_inactive_list+0x1e5/0x3c0
        shrink_node_memcg+0x202/0x760
        shrink_node+0xe0/0x470
        balance_pgdat+0x2d1/0x510
        kswapd+0x220/0x420
        kthread+0xfb/0x130
        ret_from_fork+0x22/0x40
    
    and it's not immediately obvious why it happens.  It's too late in the
    rc cycle to do anything but revert for now.
    
    Link: https://lore.kernel.org/lkml/CABXGCsN9mYmBD-4GaaeW_NrDu+FDXLzr_6x+XNxfmFV6QkYCDg@mail.gmail.com/Reported-and-bisected-by: Mikhail Gavrilov's avatarMikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
    Suggested-by: default avatarJan Kara <jack@suse.cz>
    Cc: Michal Hocko <mhocko@kernel.org>
    Cc: Vlastimil Babka <vbabka@suse.cz>
    Cc: Matthew Wilcox <willy@infradead.org>
    Cc: Kirill Shutemov <kirill@shutemov.name>
    Cc: William Kucharski <william.kucharski@oracle.com>
    Cc: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    69bf4b6b
memfd.c 7.85 KB